This is an interesting study on MS and ALS. Patients have been treated with mesenchymal cells and they were followed up for 25 months.They also labelled the stem cells in some patients and did MRI of the spinal cord and brain.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3036569/
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3036569/